Rheumatoid arthritis is a chronic degenerative disease which affects a large portion of elderly, causing serious problems to patients. The pathogenesis of rheumatoid arthritis and arthritis conditions is due at first to the immune system, and subsequently to inflammatory conditions which erode the intra-articular surfaces causing deforming damages which are irreversible and painful.
Bark and branches extracts of different species of Salix have been used for unmemorable time for the treatment of articular rheumatic forms and gout. Salix extracts were, however, substantially abandoned at the end of the 19th century, when acetylsalicylic acid was synthesized by acetylation of salicylic acid, obtained by oxidation of the compounds present in Salix. However, acetylsalicylic acid and Salix extracts have substantial differences in terms of mechanisms of actions and activity on bone joints. The extracts act on the enzyme COX 2, while acetylsalicylic acid mainly acts on COX 1, which involves the well-known side effects on the gastrointestinal tract and blood coagulation, which severely restrict its prolonged use which is conversely necessary in the case of such chronic-degenerative pathologies as arthrosis and rheumatoid arthritis. As an example a saligenin enriched Salix extract is prepared according to the patent application MI2005A001349 which is herein incorporated by reference.
Andrographis paniculata has been reported to have multiple pharmacological activities. These involve the stimulation of the immune system and the reduction of inflammation. It is well known that A. paniculata extract or its main components andrographolide inhibits the synthesis of pro-inflammatory cytokines. The addition of andrographolide to an endohelid cell culture together with tumour necrosis factor (TNF) effected a concentration depended reduction of the TNF-induced enhancement of endothelial monocyte adesion, which is part of the inflammatory process.
The primary active ingredient in Andrographis paniculata extract is andrographolide, a bitter diterpenoid lactone. The extract also contains other diterpenoid lactones, diterpene glucosides, diterpene dimers and flavonoids.
An extract for use in this invention can be prepared by immersing the aerial part of Andrographis paniculata in one or more suitable solvents such as ethanol, methanol and acetone; separating the liquid from the solid residues and concentrating the liquid. The extract thus obtained may be further processed. For example impurities can be removed the ratio of the component may be varied by known methods.